On Saturday, 22 July 2017 at 02:11:27 UTC, Mike Parker wrote:
On Saturday, 22 July 2017 at 01:45:29 UTC, solidstate1991 wrote:
Due to it's convenience, I was thinking on reading and writing
file headers by creating structs mirroring the layouts of
actual headers I would need. I've seen many examples of this
in C, however I' struggling using the same methods through the
use of code.stdc.stdio, especially as I can't really trace
bugs from fread.
struct Data {
int x;
float y;
ubyte z;
}
void main() {
import core.stdc.stdio;
Data od = Data(10, 3.0f, 5);
FILE* fp = fopen("data.dat", "wb");
size_t ret = fwrite(&od, od.sizeof, 1, fp);
fclose(fp);
assert(ret == 1);
Data id;
fp = fopen("data.dat", "rb");
ret = fread(&id, id.sizeof, 1, fp);
fclose(fp);
assert(ret == 1);
assert(id.x == 10);
assert(id.y == 3.0f);
assert(id.z == 5);
}
I should add, though, that you're better off using either
std.stdio.File or std.file. Use the former if you need to make
multiple reads/writes to a file, the latter if you can pull it in
or push it out all in one go. They take arrays as arguments, so
if you have something like Data[], you can pass it directly to
the appropriate functions. To write a single instance, you'll
have to take the pointer and slice it. Either way, it's less
code, less error prone, and more idiomatic than using the C API.
